How to correctly Test a FTP download.

I'm attempting to write a unit test, preferably in PEST PHP, to verify the following method:

Data is retrieved from the 'producers' table in the database and fed into the configuration. This configuration includes FTP server access details.

The file is then downloaded and saved locally.

How do you test something like this? Ideally, I would create a producer factory and then check if the file has been downloaded. However, I would like to avoid downloading real data if possible.

this is my simplified class:

class FtpConnection extends Connection
{

    public function download()
    {
        // get the code and make sure it's utf-8 encoded
        $file = $this->encode(
            $this->getFile()
        );

        // save content localy
        return Storage::disk($this->disk)
            ->put($this->fileName(), $file);
    }

    protected function getFile()
    {
        $config = $this->config();

        $storage = Storage::createFtpDriver($config);

        throw_if(!$storage->exists($this->producer->path), new Exception('File not found at path: ' . $this->producer->path));

        return $storage->get($this->producer->path);
    }

    protected function encode($file)
    {
        $currentEncoding = mb_detect_encoding($file, 'UTF-8, ISO-8859-1, GBK');

        if($currentEncoding != 'UTF-8') {
            return mb_convert_encoding($file, 'UTF-8', $currentEncoding);
        } else {
            return $file;
        }
    }

    protected function config(): array
    {
        return [
            'driver' => $this->producer->type,
            'host' => $this->producer->host,
            'port' => $this->producer->port,
            'username' => $this->producer->username,
            'password' => Crypt::decryptString($this->producer->password),
        ];
    }
}

martinbean

2 years ago

Level 80

@gregostry This would be an integration test; not a unit test. You can also use the Storage mocks to test. Mock the FTP disk and then ensure your code does what it should with a successful response from the FTP disk.

1 like

GregOstry

2 years ago

Level 17

it('downloads a file from ftp server successfully', function() {
    Storage::fake('ftp');

    $producer = Producer::factory()->make([
        'producer_id' => 'exampleId',
        'file_extension' => 'csv',
        'type' => 'ftp',
        'host' => 'ftp.example.com',
        'port' => 21,
        'username' => 'user',
        'password' => Crypt::encryptString('password'),
    ]);

    (new \Tests\Mock\FakeFtpConnection($producer))->download();

    Storage::disk('ftp')->assertExists('exampleId.csv');
});

I have created a FakeFtpConnection class that extends the FtpConnection class and overrides the download method. Thus, my mock class looks like this:

class FakeFtpConnection extends FtpConnection
{
    public function download(): bool
    {
        return Storage::fake('ftp')->put($this->fileName(), 'test');
//        UploadedFile::fake()->create($this->fileName());
    }
}

With this custom mock my test is passing. Is this solution approach correct? I don't know why this UploadedFile::fake() is not working...

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